The present invention relates to portable tray warming units. In particular this invention relates to an auxiliary unit to be used with the food serving system described in our U.S. Pat. No. 3,924,100 issued Dec. 2, 1975 for a food serving system and assigned to the assignee of this application. The dimension and weight of the casing are small enough so that the unit may be conveniently lifted and carried about and typically may be used in an institutional feeding system as a bedside appliance to maintain food warm until the patient is ready to eat.
Our earlier U.S. Pat. No. 3,924,100 describes a food serving system that includes a motor driven cart designed to carry approximately twenty individual food serving trays which in turn carry the bowls, plates, cups, etc. for the food being served. The cart carries its own energy source which is connected automatically to heating elements in the separate trays so as to maintain the food in certain of the bowls and plates at the desired temperature. The system has general application in the institutional feeding field, and it is particularly suitable for use in hospitals, nursing homes and other institutions where meals are served at other than in central dining facilities. The present invention is described in terms of that application, but the invention is not to be so limited. When food is served by that system in hospitals, the trays are removed from the cart in the corridor and delivered to the patients' rooms. The invention of the present application is compatible with and serves as an extension of the system of U.S. Pat. No. 3,924,100 and provides for the temperature maintenance of the food on the trays when the trays are removed from the cart and delivered to the hospital room.
In the past, meals delivered to patients who were not in their rooms during meal time have either been allowed to cool in the room until the patient returned or the meals have been returned to the kitchen or discarded. The present invention is designed to maintain food at the proper temperature until it is eaten and avoid the waste which now occurs.
The tray warming unit of this invention has several advantages. It provides a method of eliminating food waste, inefficient use of labor, and interference in the meal timing cycle within the hospital or other institution in which it's used. It provides immediate, on-hand service wherever it is needed such as at nursing stations or floor pantries. The unit is of table top size and plugs into a standard 115 volt wall outlet. The unit is also stackable so that several identical units may be used at one location and require only a small surface area.
The unit is designed to accept the food tray shown in applicant's earlier application, supra, and controls are provided on the unit to permit separate and selective activation of the heaters in the trays. By use of the combination of tray and unit, the food in the dishes and plates on the trays may be maintained between 140.degree. and 160.degree. F., the ideal serving temperature required to prevent nutritional loss and bacterial growth. While the hot food is maintained at the desired temperature, the other foods on the tray are unaffected because of the particular tray and unit design.
This invention also has application directly on the cart shown in U.S. Pat. No. 3,924,100. When the capacity of the cart falls somewhat short of what is actually required, for example 22 or 24 trays, one or two of the portable units of this invention may be stacked directly on the cart to form an extention thereof during delivery of the trays.